Carotid endarterectomy before and after publication of randomized controlled trials

Background: In 1991, the European Carotid Surgery Trial (ECST) and the North American Symptomatic Carotid Endarterectomy Trial (NASCET) demonstrated that carotid endarterectomy (CEA), in addition to best medical therapy, significantly reduces ipsilateral stroke in patients with high-grade (70 per cent or more) carotid artery stenosis compared with best medical therapy alone. In 1995, the Asymptomatic Carotid Atherosclerosis Study demonstrated that CEA was of benefit in asymptomatic patients with stenosis greater than 60 per cent. The aim of this paper was to examine how the practice and outcome of CEA have changed since publication of these data. Methods: A prospectively gathered computerized database comprising 634 consecutive CEAs was studied. Two time intervals were analysed: 1975-1991 inclusive (17 years) and 1 January 1992 to 1 May 1998 (6 years 4 months). Results: Since 1991, there has been a fourfold increase in the number of CEAs performed annually for symptomatic disease. CEA is now performed almost exclusively for high-grade (more than 70 per cent) stenosis. There has been a significant reduction in the total peri-operative neurological event rate (12.5 versus 5.9 per cent, P < 0.05), and the 30-day combined major stroke (Rankin grade 3-5) and mortality rate has fallen to 2.0 per cent. The number of patients who have CEA for asymptomatic disease remains small with 16 of 30 being randomized within the Asymptomatic Carotid Surgery Trial. Conclusion: Publication of ECST and NASCET data has been associated with a major increase in the number of CEAs performed for symptomatic disease in this unit. Despite a greater proportion. of highrisk patients, the results have improved progressively.